I would definitely say go with Easy Scorecard Pro on Android. It's not very expensive, and it is a great app that can calculate a round rating for you based on an SSE. You can also have it search for local courses that are on its database then download the course par/distance info straight to your phone. There is also a GPS feature that you can use if you wanted to get exact distances on alternate pin positions (I have yet to learn that feature :/ )